U.S. patent application number 11/205169 was filed with the patent office on 2005-12-22 for device manufacturing method and device, electro-optic device, and electronic equipment.
This patent application is currently assigned to SEIKO EPSON CORPORATION. Invention is credited to Hashimoto, Takashi, Kamakura, Tomoyuki, Takakuwa, Atsushi, Utsunomiya, Sumio.
Application Number | 20050280041 11/205169 |
Document ID | / |
Family ID | 32902944 |
Filed Date | 2005-12-22 |
United States Patent
Application |
20050280041 |
Kind Code |
A1 |
Hashimoto, Takashi ; et
al. |
December 22, 2005 |
Device manufacturing method and device, electro-optic device, and
electronic equipment
Abstract
A device manufacturing method, including: a first process for
providing the plural elements on the original substrate via a
separation layer in a condition where terminal sections are exposed
to a surface on an opposite side to the separation layer; a second
process for adhering the surface where the terminal sections of the
elements to be transferred on the original substrate are exposed,
via conductive adhesive, to a surface of the final substrate on a
side where conductive sections for conducting with the terminal
sections of the elements are provided; a third process for
producing exfoliation in the separation layer between the original
substrate and the final substrate; and a fourth process for
separating the original substrate from which the transfer of
elements has been completed, from the final substrate.
Inventors: |
Hashimoto, Takashi;
(Chino-shi, JP) ; Takakuwa, Atsushi;
(Shiojiri-shi, JP) ; Kamakura, Tomoyuki;
(Matsunota-shi, JP) ; Utsunomiya, Sumio;
(Suwa-shi, JP) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 19928
ALEXANDRIA
VA
22320
US
|
Assignee: |
SEIKO EPSON CORPORATION
TOKYO
JP
|
Family ID: |
32902944 |
Appl. No.: |
11/205169 |
Filed: |
August 17, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11205169 |
Aug 17, 2005 |
|
|
|
10756416 |
Jan 14, 2004 |
|
|
|
Current U.S.
Class: |
257/213 ;
257/E27.111; 257/E27.113; 257/E29.295 |
Current CPC
Class: |
H01L 27/13 20130101;
H01L 27/1266 20130101; H01L 2221/68381 20130101; H01L 2221/68363
20130101; H01L 29/78603 20130101; H01L 21/6835 20130101; H01L
27/1214 20130101; H01L 2221/68322 20130101 |
Class at
Publication: |
257/213 |
International
Class: |
H01L 029/745 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 23, 2003 |
JP |
2003-015097 |
Claims
What is claimed is:
1. A device comprising elements provided on a substrate, wherein
terminal sections are provided in an exposed condition on a surface
of said elements on the substrate side, and conductive sections for
conducting with the terminal sections of said elements are provided
on the surface of said substrate on the side where the elements are
provided; and said elements are adhered to said substrate by a
conductive adhesive which conducts between said terminal sections
and said conductive sections.
2. A device according to claim 1, wherein said conductive adhesive
is an anisotropic conductive adhesive.
3. A device according to claim 1, wherein there are plural terminal
sections of said elements, and the conductive adhesives to be
adhered to these terminal sections are formed in a condition of
independence for each of the respective terminal sections, and
between the independent conductive adhesives is insulated.
4. A device according to claim 3, wherein said conductive adhesives
are in the independent condition by arranging the conductive
adhesives separated for each of the respective terminal sections,
and between the conductive adhesives is insulated.
5. A device according to claim 3, wherein said conductive adhesives
are in the independent condition for each of the respective
terminal sections by separating by an insulative partition, and
between the conductive adhesives is insulated.
6. A device according to claim 3, wherein said conductive adhesives
are in the independent condition for each of the respective
terminal sections by arranging into respectively independent
concavities, and between the conductive adhesives is insulated.
7. An electro-optic device equipped with a device according to
claim 1.
8. An electronic equipment equipped with a device according to
claim 1.
Description
[0001] This is a Division of application Ser. No. 10/756,416 filed
Jan. 14, 2004. The entire disclosure of the prior application is
hereby incorporated by reference herein in its entirety. Priority
is claimed on Japanese Patent Application No. 2003-15097, filed
Jan. 23, 2003, the content of which is incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a manufacturing method for
a device which manufactures a device by transferring elements, a
device manufactured by the method, an electro-optic device, and
electronic equipment.
[0003] Recently, for electro-optic devices such as liquid crystal
electro-optic devices, active matrix type devices which use thin
film elements such as thin film transistors (hereunder, TFT), thin
film diodes (hereunder, TFD) or the like, have become the
mainstream. However, regarding the conventional electro-optic
devices furnished with amorphous silicon TFT or polycrystalline
silicon TFT, manufacturing cost per unit area is expensive. Hence,
in the case where large electro-optic devices are to be
manufactured, a problem is that the cost becomes very expensive.
One cause for this is the effective area utilization ratio of the
transistor circuit on the substrate of the liquid crystal
electro-optic device is low, and wastage of the thin film element
constituent material which forms the film is considerable. That is
to say, in the case where amorphous silicon TFT or polycrystalline
silicon TFT are to be formed on the substrate by the conventional
techniques, after film-forming the amorphous silicon on one side by
CVD or the like, the unnecessary parts are removed by etching.
However, the TFT circuit area inside the pixel area is only from a
few % to several 10% and the thin film element constituent material
which is film-formed on the rest of pixel electrode part is
discarded by etching. In cases where it is possible to effectively
manufacture only the TFT circuit section on the substrate, it is
possible to greatly reduce the cost, especially of large
electro-optic devices. Therefore various techniques have been
studied.
[0004] Conventionally, as a technique for arranging an LSI circuit
which is manufactured on a silicon wafer, onto another substrate, a
so called microstructure method developed by Alien Technology Co.
is well known (for example, refer to the Information DISPLAY, Vol.
15, No. 11 (November 1999)).
[0005] The microstructure technique is characterized in that it
involves separating LSI circuits manufactured on a silicon wafer
into microchips (=microstructures), and then pouring solvent
dispersed with the microstructures onto a substrate previously
patterned with holes for filling, so that the microstructures are
arranged at predetermined positions on the substrate. According to
this microstructure technique, microstructures which are formed in
a large number on a silicon wafer can be dispersingly arranged on a
substrate. Moreover, since this gives a discrete type arrangement
where unit elements are separated on the substrate, the ability to
follow the curvature and bending of the substrate is excellent, so
that it is applicable to flexible substrates.
[0006] However, in the microstructure technique, there is the
problem in that reliable arrangement of the microstructures on the
substrate and accurate positioning are difficult. Moreover, since
the directions in which the microstructures are arranged are
random, special circuits to cope with this must be provided for the
microstructures, with the problem of incurring a cost increase. In
the present state, this problem is avoided by designing the
circuits on microstructures in four-way symmetry.
[0007] Further, in the manufacture of color filters of liquid
crystal displays, a method called an LITI process is well known, in
which; a donor sheet formed by the sequential lamination of
respective layers of; substrate/adhesion layer/optical absorption
layer/protective layer/colored film layer/thermal melting adhesion
layer, is superposed on an original substrate; the optical
absorption layer is then photoirradiated for a partial area of the
donor sheet; heat generated here melts and adheres the thermal
melting adhesion layer; and as a result only the photoirradiated
area is transferred onto the substrate (for example, refer to the
U.S. Pat. No. 6,057,067).
[0008] However, this conventional technique is used for
manufacturing color filters or the like for liquid crystal display
elements, and other application possibilities have not been
specified.
[0009] Furthermore, as a method for transferring a thin film
element such as a TFT or the like formed on a substrate, to a
transfer body, the present applicant has developed and applied to
patent, a transferring method for a thin film element, which is
characterized in having; a process for forming a separation layer
on a substrate of high reliability and which can transmit laser
light; a process for forming a transfer layer containing a thin
film element on the separation layer; a process for adhering the
transfer layer containing the thin film element to the transfer
body via an adhesion layer; a process for photoirradiating the
separation layer and generating exfoliation in the layer and/or on
interface of the separation layer; and a process for separating the
substrate from the separation layer (refer to the Japanese Patent
Application No. Hei 10-125931).
[0010] Likewise, the present applicant has developed and applied to
patent a method for transferring a thin film element, which is
characterized in having: a first process for forming a first
separation layer on a substrate; a second process for forming a
transfer layer containing a thin film device on the first
separation layer; a third process for forming a second separation
layer on the transfer layer; a fourth process for adhering a
primary transfer body on the second separation layer, a fifth
process for removing the substrate from the transfer layer with the
first separation layer made a border, a sixth process for adhering
a secondary transfer body on the undersurface of the transfer
layer, and a seventh process for removing the primary transfer body
from the transfer layer with the second separation layer made a
border; and the transfer layer containing the thin film device is
transferred to the secondary transfer body (refer to the Japanese
Patent Application No. Hei 11-26733).
[0011] According to these transferring techniques, it is possible
to transfer a detailed and high performance functional device onto
a desired substrate.
[0012] However, the conventional transfer techniques have the
following problems.
[0013] That is to say, since the conventional transfer techniques
are to transfer all of the thin film elements such as TFTs which
are formed on the substrate onto the final substrate, then as with
an active matrix substrate for electro-optic devices, a large
number of TFTs are required. However, in order to manufacture a
substrate for which the arranged area of the TFTs is small with
respect to the whole substrate area, it is necessary to specially
manufacture a substrate where a large number of TFTs are formed at
the same intervals as for the final substrate, and transfer these
to the final substrate, or it is necessary to repeat the transfer
many times, which does not always give a reduction in cost.
[0014] Further, since the conventional transfer techniques are to
transfer all the thin film elements such as TFTs which are formed
on the substrate onto the final substrate, then the larger the area
of the substrate, the higher the characteristic required for the
irradiating laser light, that is, the higher the power and
uniformity, so that it becomes difficult to obtain a laser light
source which satisfies the required performance, and large sized
highly accurate irradiation equipment becomes necessary for the
laser light irradiation. In addition, when irradiating a high power
laser light, the thin film elements may be heated above their heat
resistant critical temperature, so that the function of the thin
film element itself may be lost. Hence, there is the problem that
the transfer process itself becomes difficult.
[0015] Furthermore, similarly to the conventional transfer
techniques, in the case where the thin film elements formed on the
substrate are transferred for each device, for example, an
insulating film is continuously formed over the whole surface of
the thin film element. Therefore cracking may occur when the final
substrate is bent after the transfer, and the ability to follow the
bending of the substrate is not good. As a result, in the
conventional transfer techniques, the degree of freedom for
selecting the final substrate is limited.
SUMMARY OF THE INVENTION
[0016] The present invention takes into consideration the above
situation with the object of providing, a manufacturing method for
a device which enables the manufacture of a device effectively at
low cost, by dispersingly arranging elements such as TFTs on a
final substrate which becomes an active matrix substrate for an
electro-optic device, and a device which can be manufactured
effectively at low price, and an electro-optic device and
electronic equipment equipped with such a device.
[0017] In order to achieve the above object, a manufacturing method
for a device of the present invention, in which some or all of
plural elements formed on an original substrate are transferred to
a final substrate, and some or all of the transferred elements are
used to manufacture the device, including: a first process for
providing the plural elements on the original substrate via a
separation layer in a condition where terminal sections are exposed
to a surface on an opposite side to the separation layer; a second
process for adhering the surface where the terminal sections of the
elements to be transferred on the original substrate are exposed,
via conductive adhesive, to a surface of the final substrate on a
side where conductive sections for conducting with the terminal
sections of the elements are provided; a third process for
producing exfoliation in the separation layer between the original
substrate and the final substrate; and a fourth process for
separating the original substrate from which the transfer of
elements has been completed, from the final substrate.
[0018] According to the manufacturing method for a device of the
present invention, it is possible to concentratedly manufacture,
for example on the original substrate, the many elements which are
to be dispersingly arranged at intervals on the final substrate.
Hence, compared to the case where elements are directly formed on
the final substrate, it is possible to greatly increase the area
efficiency of the substrate when manufacturing elements.
Consequently, it becomes possible to manufacture effectively and at
low cost, a final substrate where many elements are dispersingly
arranged. As a result, the device itself can be effectively
manufactured at low cost.
[0019] Moreover, it possible to easily execute prior to transfer,
selection and removal of bad quality elements from the many
elements which are concentratedly arranged on the original
substrate. As a result, product yield rate can be increased.
[0020] Since the surface where the terminal sections of the
elements are exposed is adhered via the conductive adhesive to the
final substrate, then for example, by directly adhering the
conductive adhesive to the conductive sections on the final
substrate, adhesion of the elements to the final substrate and
conducting the terminal sections with the conductive sections can
be performed at the same time. Hence, the process for conducting
the terminal sections with the conductive sections by wiring after
transferring becomes unnecessary.
[0021] Furthermore, it is possible to laminate and unite the same
or different elements. Therefore, by uniting the elements
manufactured under different process conditions, an element having
a laminated structure which is conventionally difficult to
manufacture can be provided, and an element having a
three-dimensional structure can be easily manufactured.
[0022] Furthermore, in the manufacturing method, preferably the
original substrate is a substrate for forming elements.
[0023] In this manner, when forming elements on the original
substrate, the terminal sections thereof may be arranged on the
opposite side to the original substrate, that is, the outer side.
Hence, it becomes easy to form the terminal sections.
[0024] In the manufacturing method, preferably the conductive
adhesive is an anisotropic conductive adhesive.
[0025] In this manner, for example, in the case where there are
plural terminal sections of the elements, and the conductive
sections are respectively conducted to these terminal sections, the
terminal sections and the corresponding conductive sections are
arranged to oppose each other, and are adhered by the anisotropic
conductive adhesive, and pressed, so that the anisotropic
conductive adhesive can demonstrate the anisotropy thereof and
conduct only between the opposing terminal sections and conductive
sections. Hence, it is not necessary to form the conductive
adhesive in a condition of independence for each of the respective
terminal sections. As a result, productivity is extremely good.
[0026] In the case where the conductive adhesive is an anisotropic
conductive adhesive, then preferably in the second process,
film-like adhesive is used as the conductive adhesive, and this
film-like adhesive is formed on the surface on the side where the
terminal sections of the element are exposed, or to the position to
be connected to the terminal sections on the surface of the final
substrate on the side where the conductive sections are
provided.
[0027] In this manner, since this is film-like adhesive, it becomes
easy to handle the conductive adhesive, and hence productivity can
be increased. In the manufacturing method, preferably in the second
process, the conductive adhesive is provided between the elements
and the final substrate in liquid form, and then cured.
[0028] In this manner, the degree of freedom in selecting the
application method; such as for example overall coating by spin
coating, selective coating by a liquid droplet discharge method, or
various printing methods, is higher, so that it becomes possible to
select the suitable application method corresponding to the type of
element.
[0029] In the case where the conductive adhesive is liquid form,
preferably the conductive adhesive is selectively arranged by a
liquid droplet discharge method.
[0030] In this manner, since the conductive adhesive can be
arranged at only the desired position, then for example, by
arranging the conductive adhesive only at the places corresponding
to the elements to be transferred, loss of the adhesive can be
reduced. Moreover, transfer of the elements to the final substrate
can be done easily.
[0031] Preferably in the case where the conductive adhesive is
selectively arranged by the liquid droplet discharge method, prior
to this, the position where the conductive adhesive for the
elements or for the final substrate is arranged is subjected to a
lyophilic treatment, and/or the surroundings of the position where
the conductive adhesive is arranged is subjected to a liquid
repellent treatment.
[0032] In this way, even in the case where the droplets are
discharged, shifted from the desired position, due to the liquid
repellent treatment, the droplets are repelled to the desired
position, and as a result are applied to the desired position.
Furthermore, the droplets discharged to the desired position, due
to the lyophilic treatment, stay in that position and do not flow
to the surroundings.
[0033] Preferably in the case where the conductive adhesive is
selectively arranged by the liquid droplet discharge method, prior
to this, a partition is formed to enclose the position where the
conductive adhesive for the elements or for the final substrate is
arranged, and then, the conductive adhesive is selectively arranged
within the partition.
[0034] In this manner, by arranging the conductive adhesive by
discharging within the partition, the conductive adhesive can be
more reliably applied to the desired position.
[0035] In the case where the conductive adhesive is selectively
arranged by the liquid droplet discharge method, prior to this, it
is preferable to form a concavity at a junction position of the
elements with the final substrate, and then to selectively arrange
the conductive adhesive in the concavity.
[0036] In this manner, by arranging the conductive adhesive by
discharging into the concavity, the conductive adhesive can be more
reliably applied to the desired position. Furthermore, for example,
in the case where the concavity is formed in a shape to fit the
element, then by fitting the element to the concavity, positioning
is possible when adhering the original substrate and the final
substrate. Hence, positioning when adhering the substrates can be
easily and accurately performed. Furthermore, by fitting the
element into the concavity, it is possible to thin the substrate
where the elements are mounted (the final substrate).
[0037] In the case where a concavity is formed at the junction
position of the element with the final substrate, and the
conductive adhesive is then selectively arranged in the concavity,
it is preferable to provide beforehand in the concavity, conductive
sections for conducting with the terminal sections of the
elements.
[0038] In this manner, adhering the elements to the final
substrate, and conducting the terminal sections with the conductive
sections can be performed at the same time. Hence, the process
after transferring, for conducting the terminal sections with the
conductive sections by wiring becomes unnecessary.
[0039] In the manufacturing method, in a case where there are
plural terminal sections of the elements, it is preferable to form
the conductive adhesive to be formed on these terminal sections in
a condition of independence for each of the respective terminal
sections, and to insulate between the independent conductive
adhesives.
[0040] In this manner, even if the conductive adhesive is not an
anisotropic conductive adhesive but a general one, short-circuits
between the terminal sections by the conductive adhesive can be
prevented.
[0041] The device of the present invention is characterized in
that, in a device including elements provided on a substrate,
terminal sections are provided in an exposed condition on a surface
of the elements on the substrate side, and conductive sections for
conducting with the terminal sections of the elements are provided
on the surface of the substrate on the side where the elements are
provided; and the elements are adhered to the substrate by a
conductive adhesive which conducts between the terminal sections
and the conductive sections.
[0042] According to this device, since the surface where the
terminal sections of the elements are exposed, is adhered via the
conductive adhesive to the conductive sections on the substrate,
then at the time of manufacture, a process for mounting the
elements on the substrate and a process for conducting the terminal
sections of elements with the conductive sections of the substrate
are performed at the same time. Therefore, a process after mounting
for conducting the terminal sections with the conductive sections
by wiring becomes unnecessary, giving high productivity.
[0043] In the device, preferably the conductive adhesive is an
anisotropic conductive adhesive.
[0044] In this manner, for example, in the case where there are
plural terminal sections of the elements, and the conductive
sections are respectively conducted with these terminal sections,
the terminal sections and the corresponding conductive sections are
arranged to oppose each other, and are adhered by the anisotropic
conductive adhesive, and pressed, so that the anisotropic
conductive adhesive can demonstrate the anisotropy thereof and
conduct only between the opposing terminal sections and conductive
sections. Hence, it is not necessary to form the conductive
adhesive in a condition of independence for each of the respective
terminal sections. As a result, productivity is extremely good.
[0045] Moreover, preferably in the device there are plural terminal
sections of the elements, and the conductive adhesives to be formed
on these terminal sections are formed in a condition of
independence for each of the respective terminal sections, and
between the independent conductive adhesives is insulated.
[0046] In this manner, even if the conductive adhesive is not an
anisotropic conductive adhesive but a general one, short-circuits
between the terminal sections by the conductive adhesive can be
prevented.
[0047] In the case where the conductive adhesive to be formed on
the terminal sections is formed in a condition of independence for
each of the respective terminal sections, and between the
independent conductive adhesives is insulated, it is preferable
that the conductive adhesives are in the independent condition by
arranging these conductive adhesives separated for each of the
respective terminal sections, and between the conductive adhesives
is insulated.
[0048] In this manner, short-circuits between the terminal sections
by the conductive adhesive can be reliably prevented.
[0049] Moreover, in the case where the conductive adhesive to be
adhered to the terminal sections is formed in a condition of
independence for each of the respective terminal sections, and
between the independent conductive adhesives is insulated, it is
preferable that the conductive adhesives are in the independent
condition for each of the respective terminal sections by
separating by an insulative partition, and between the conductive
adhesives is insulated.
[0050] In this manner, short-circuits between the terminal sections
by the conductive adhesive can be reliably prevented.
[0051] Furthermore, in the case where the conductive adhesive to be
adhered to the terminal sections is formed in a condition of
independence for each of the respective terminal sections, and
between the independent conductive adhesive is insulated, it is
preferable that the conductive adhesives are in the independent
condition for each of the respective terminal sections by arranging
into respectively independent concavities, and between the
conductive adhesives is insulated.
[0052] In this manner, short-circuits between the terminal sections
by the conductive adhesive can be reliably prevented.
[0053] Moreover, the device of the present invention is
characterized in being obtained by the manufacturing methods
according to any one of the above aspects.
[0054] According to this device, it is manufactured effectively at
low cost, and product yield rate is also increased.
[0055] The electro-optic device of the present invention is
characterized in being equipped with the aforementioned device.
[0056] According to this electro-optic device, the device is
manufactured effectively at low cost and product yield rate is also
increased, so that the electro-optic device itself is also
manufactured at low cost.
[0057] The electronic equipment of the present invention is
characterized in being equipped with the aforementioned device.
[0058] According to this electronic equipment, the device is
manufactured effectively at low cost and product yield rate is also
increased, so that the electronic equipment itself is also
manufactured at low cost.
[0059] As described above, according to the manufacturing method
for a device of the present invention, plural elements which are to
be dispersingly arranged at intervals on the final substrate are
concentratedly manufactured on the original substrate. Therefore,
devices can be manufactured effectively at low cost.
[0060] Moreover, the plural elements which are concentratedly
manufactured on the original substrate can be easily selected and
removed before the transfer. As a result, product yield rate can be
increased.
[0061] Furthermore, since the surface where the terminal sections
of the elements are exposed is adhered via the conductive adhesive
to the final substrate, then for example, by directly adhering the
conductive adhesive to the conductive sections on the final
substrate, adhesion of the elements to the final substrate and
conducting the terminal sections with the conductive sections can
be performed at the same time. Hence, the process for conducting
the terminal sections with the conductive sections by wiring after
transferring is obviated, enabling simplification of the processes
and an increase in productivity.
[0062] Moreover, an element having a laminated structure which is
conventionally difficult to manufacture can be provided, and an
element having a three-dimensional structure can be easily
manufactured.
BRIEF DESCRIPTION OF THE DRAWINGS
[0063] FIG. 1 is an explanatory diagram of a first embodiment of a
device of the present invention, and a side cross-section showing a
first process for forming a separation layer on an original
substrate.
[0064] FIG. 2A to 2C are explanatory diagrams of a second process
for forming many elements on a separation layer, FIG. 2A is a side
cross-section showing a condition where many elements are formed on
the separation layer, FIG. 2B is an enlarged side cross-section of
a main part for describing another example of formation, and FIG.
2C is an enlarged side cross-section for showing a device.
[0065] FIG. 3A is a side cross-section showing a condition where
electrode pads are formed on a final substrate, FIG. 3B is a side
cross-section showing a condition where wiring 30 is connected to
the electrode pads, and FIG. 3C is a bottom view schematically
showing an arrangement of terminal sections of elements and the
electrode pads.
[0066] FIG. 4 is a side cross-section showing a condition where a
film-like anisotropic conductive adhesive is adhered to a final
substrate.
[0067] FIG. 5 is a side cross-section showing a process for
superposing the original substrate on the final substrate and
adhering them.
[0068] FIG. 6 is a side cross-section showing a process for
producing exfoliation in a separation layer by partially
irradiating light from the original substrate side.
[0069] FIG. 7 is a side cross-section showing a process for
removing the original substrate from the final substrate after
transferring.
[0070] FIG. 8 is a schematic diagram for explaining a condition
where many elements are transferred onto the final substrate.
[0071] FIG. 9 is a side cross-section showing a condition where
film-like anisotropic conductive adhesive is adhered only to the
element transferring area of the final substrate.
[0072] FIG. 10 is a side cross-section showing a condition where
liquid form anisotropic conductive adhesive is applied onto the
whole surface of the final substrate by spin coating.
[0073] FIG. 11 is a side cross-section showing a condition where
liquid form anisotropic conductive adhesive is arranged on the
electrode pads of the final substrate by a liquid droplet discharge
method.
[0074] FIGS. 12A and 12B are diagrams for explaining the schematic
configuration of an inkjet head, FIG. 12A is a perspective view of
the main parts and FIG. 12B is a side cross-section of the main
parts.
[0075] FIG. 13A to 13C are side cross-sections for explaining a
method of applying an anisotropic conductive adhesive using a
stamper.
[0076] FIG. 14 is a side cross-section showing a condition where
liquid form anisotropic conductive adhesive is arranged on the
electrode pads of the final substrate using partitions, by a liquid
droplet discharge method.
[0077] FIG. 15 is a side cross-section showing a condition where
liquid form anisotropic conductive adhesive is arranged inside
concavities in the final substrate, by a liquid droplet discharge
method.
[0078] FIG. 16 is a side cross-section showing a condition where
conductive adhesive is independently provided for the electrode
pads formed on the final substrate.
[0079] FIG. 17 is a side cross-section showing a condition where
conductive adhesive is independently provided for the electrode
pads formed on the final substrate by forming partitions.
[0080] FIG. 18 is a side cross-section showing a condition where
conductive adhesive is provided inside concavities formed in the
final substrate.
[0081] FIG. 19A to 19C are diagrams showing electronic equipment
related to the present invention, FIG. 19A shows an example of a
mobile phone, FIG. 19B shows an example of a portable information
processor, and FIG. 19C shows an example of a watch type electronic
equipment.
DETAILED DESCRIPTION OF THE INVENTION
[0082] Hereunder is a description of embodiments of the present
invention, with reference to the drawings.
First Embodiment
[0083] FIG. 1 to FIG. 7 are explanatory drawings of a first
embodiment of the present invention (element transfer method). This
element transfer method is an example of where an anisotropic
conductive adhesive film is specifically used as a conductive
adhesive, and is executed through the following first process to
fourth process.
[0084] [First Process]
[0085] In the first process, as shown in FIG. 1, a separation layer
11 is formed on an original substrate 10, and furthermore, as shown
in FIG. 2A, many elements 12 are formed on the separation layer
11.
[0086] The original substrate 10 in the present embodiment, is a
substrate for element forming. Such an element forming substrate is
preferably one having transmittance that allows transmission of
light.
[0087] In this case, the transmissivity of light is preferably more
than 10%, and more preferably more than 50%. If the transmissivity
is too low, the loss of light becomes large, and a larger quantity
of light is required in order to exfoliate the separation layer
11.
[0088] Moreover, preferably the original substrate 10 is
constructed from highly reliable material, specifically, it is
preferably constructed from materials with superior heat
resistance. The reason is that for example, when forming an element
12 or intermediate layer 16 described later, the process
temperature may become high depending on the type or formation
method (for example, around 350 to 1000.degree. C.). However, even
in such a case, if the substrate 10 is superior in heat resistance,
then when forming the element 12 on the original substrate 10, the
range of settings for the film forming conditions such as the
temperature conditions and the like, can be wider.
[0089] Therefore, if the maximum temperature when forming the
element 12 is Tmax, the original substrate 10 is preferably
manufactured from a material with a distortion point greater than
Tmax. Specifically, the constituent material for the original
substrate 10, preferably has a distortion point greater than
350.degree. C., and more preferably has a distortion point greater
than 500.degree. C. As such materials, heat resistant glass such as
quartz glass, Corning 7059, and OA-2 made by Nippon Electric Glass
Co. are given as examples.
[0090] The thickness of the original substrate 10 is not
specifically limited. However it is preferably around 0.1 to 5.0
mm, and more preferably around 0.5 to 1.5 mm. If the thickness of
the original substrate 10 is too thin, the strength drops, while if
too thick, then in the case where the transmissivity of the
original substrate 10 is low, attenuation of light can easily
occur. In the case where the transmissivity of the original
substrate 10 is high, the thickness may be greater than the
aforementioned upper limit. In order to evenly irradiate the light,
the thickness of the original substrate 10 is preferably
uniform.
[0091] The separation layer 11 is formed by materials which easily
produce exfoliation by the action of mechanical force. That is to
say, it is formed by such materials that; when a force acting on
the separation layer 11 in a direction to separate the original
substrate 10 and a later described final substrate, is applied from
one edge of those substrates, it easily produces exfoliation in the
layer and/or on the interface of the separation layer 11
(hereunder, "internal exfoliation" and "interfacial
exfoliation").
[0092] Furthermore, such a separation layer 11 preferably has a
characteristic of absorbing irradiated light and producing
exfoliation in the layer and/or on the interface, that is to say,
internal exfoliation and/or interfacial exfoliation. Specifically,
it is desired that the interatomic or intermolecular binding
strength of the constituent material of the separation layer 11 is
eliminated or reduced by light irradiation, that is, ablation is
produced ending in internal exfoliation and/or interfacial
exfoliation.
[0093] Furthermore, in some cases gas will be released from the
separation layer 11 by the light irradiation, to manifest the
separation effect. That is to say, there is the case where an
element contained in the separation layer 11 becomes a gas and is
released, and the case where the separation layer absorbs the light
and instantly becomes a gas and the vapor thereof is released to
contribute to the separation.
[0094] Examples of the constituent materials for the separation
layer 11, are those described in A-F hereunder.
[0095] A. Amorphous Silicon (a-Si)
[0096] This amorphous silicon may contain hydrogen (H). In this
case, it is preferable that the H content be approximately 2 atomic
percent or more, and more preferably 2 to 20 atomic percent. When a
predetermined amount of hydrogen (H) is contained in this manner,
hydrogen is released by light irradiation and an internal pressure
is generated in the separation layer 11, becoming a force to
separate the upper and lower thin films. The hydrogen (H) content
in the amorphous silicon can be controlled by appropriately setting
the film forming conditions, for example, the gas composition, gas
pressure, gas atmosphere, gas flow rates, temperature, substrate
temperature and input power in the CVD.
[0097] B. Oxide ceramics, dielectrics (ferroelectrics) and
semiconductors, such as silicon oxides and silicates, titanium
oxides and titanates, zirconium oxide and zirconates, and lanthanum
oxide and lanthanates. Examples of silicon oxides include SiO,
SiO.sub.2, and Si.sub.3O.sub.2, and examples of silicates include
K.sub.2SiO.sub.3, Li.sub.2SiO.sub.3, CaSiO.sub.3, ZrSiO.sub.4, and
Na.sub.2SiO.sub.3.
[0098] Examples of titanium oxides include TiO, Ti.sub.2O.sub.3,
and TiO.sub.2, and examples of titanates include BaTiO.sub.4,
BaTiO.sub.3, Ba.sub.2Ti.sub.9O.sub.20, BaTi.sub.5O.sub.11,
CaTiO.sub.3, SrTiO.sub.3, PbTiO.sub.3, MgTiO.sub.3, ZrTiO.sub.2,
SnTiO.sub.4, Al.sub.2TiO.sub.5 and FeTiO.sub.3.
[0099] Examples of zirconium oxides include ZrO.sub.2, and examples
of zirconates include BaZrO.sub.2, ZrSiO.sub.4, PbZrO.sub.3,
MgZrO.sub.3 and K.sub.2ZrO.sub.3.
[0100] C. Ceramics and dielectrics (ferroelectrics), such as PZT,
PLZT, PLLZT, PBZT.
[0101] D. Nitride ceramics, such as silicon nitride, aluminum
nitride, titanium nitride.
[0102] E. Organic Polymers:
[0103] Usable organic polymers have linkages (which are cut by
irradiation of the light), such as --CH--, --CO-- (ketone),
--CONH-- (amide), --NH-- (imide), --COO-- (ester), --N.dbd.N--
(azo), --CH.dbd.N-- (cis). In particular, any organic polymers
having large numbers of such linkages can be used. The organic
polymers may have aromatic hydrocarbons (one or more benzene rings
or fused rings) in the chemical formulae.
[0104] Examples of the organic polymers include polyolefins, such
as polyethylene, and polypropylene; polyimides; polyamides;
polyesters; polymethyl methacrylate (PMMA); polyphenylene sulfide
(PPS); polyether sulfone (PES); and epoxy resins.
[0105] F. Metals
[0106] Examples of metals include Al, Li, Ti, Mn, In, Sn, Y, La,
Ce, Nd, Pr, Gd, Sm, and alloys containing at least one of these
metals.
[0107] The thickness of the separation layer 11 depends on various
conditions, such as the purpose for exfoliation, the composition of
the separation layer 11, the layer configuration, and the method
for forming the layer. However, normally a thickness of around 1 mm
to 20 .mu.m is preferable, more preferably around 10 nm to 2 .mu.m,
and even more preferably around 40 nm to 1 .mu.m. If the film
thickness of the separation layer 11 is too small, uniformity in
deposition may be lost, and nonuniformity may occur in the
separation. If the film thickness is too thick, then in order to
maintain good peelability of the separation layer 11, it is
necessary to increase the power of light (quantity of light), and
when removing the separation layer 11 later, the operation takes
time. It is preferable that the thickness of the separation layer 2
be as uniform as possible.
[0108] The method for forming the separation layer 11 is not
limited, and is determined depending on several conditions, such as
the film composition and thickness. Examples of the methods include
vapor phase deposition processes, such as CVD (including MOCVD, low
pressure CVD, ECR-CVD), evaporation, molecular beam (MB)
evaporation, sputtering, ion-plating, and PVD; plating processes,
such as electro-plating, dip-plating (dipping), and
electroless-plating; coating process, such as a Langmuir-Blodgett
process, spin-coating process, spray-coating process, and
roll-coating process; printing processes; transfer processes;
ink-jet processes; and powder-jet processes. A combination of these
processes may also be used.
[0109] For example, when the separation layer 11 is composed of
amorphous silicon (a-Si), it is preferable that the layer be formed
by a CVD process, specifically a low pressure CVD or plasma CVD
process.
[0110] When the separation layer 11 is formed from a ceramic by a
sol-gel process, or formed from an organic polymer, it is
preferable that the layer be formed by a coating process, and
particularly a spin-coating process. Further, although not shown in
FIG. 1, depending on the properties of the original substrate 10
and the separation layer 11, an intermediate layer may be arranged
between the original substrate 10 and the separation layer 11 with
an object of increasing the adhesion of both.
[0111] If the separation layer 11 is formed in this way, then as
shown in FIG. 2A, many elements 12 are formed on the separation
layer 11, and then an etching process is performed so that the
respective elements 12 and the separation layer 11 immediately
beneath remain as islands style. The result is such that, as shown
in FIG. 2A, the many transferred layers (elements 12) are arranged
at predetermined intervals via the separation layer 11 on the
original substrate 10. In this manner, by forming the elements 12
being the transferred layers, and the separation layer 11 as
islands, it becomes easy to transfer only the desired elements 12
in an exfoliation process described later.
[0112] The separation layer 11 divided for each of the respective
elements 12, as shown in FIG. 2A, may be the same size as the
separation layer adhesion face of the element 12. However, it may
be such that, as shown in FIG. 2B, the separation layer 11 is
further over-etched so that the adhesion area of the separation
layer 11 to the element 12 becomes smaller than the whole area of
the separation layer adhesion face of element 12. In this manner,
by over-etching the separation layer 11, then when the mechanical
force is exerted on the separation layer 11, exfoliation is easily
produced at the separation layer 11. Furthermore as described
later, when irradiating light as a pre-exfoliation process,
exfoliation is easily produced. Moreover, by reducing the
separation layer 11, the amount of light energy required for
exfoliation can be reduced.
[0113] FIG. 2C is a cross-section showing an example of the element
12 used in the present embodiment. The element 12 is constructed to
contain for example a TFT (thin film transistor) formed on an
SiO.sub.2 film (intermediate layer) 16. The TFT is equipped with a
source and drain area 17 formed by introducing an n-type impurity
to the polysilicon layer, a channel area 18, a gate insulating film
19, a gate electrode 20, an interlayer insulating film 21, and a
source electrode 22 and drain electrode 22 composed of for example
aluminum. Here, the elements 12 in the present invention, as shown
in FIG. 2C, are formed in a condition where the terminal sections
of the respective electrodes are exposed to a surface 12a on the
opposite side to the separation layer 11. That is to say, the gate
electrode 20 is formed with one surface (the surface on the
opposite side to the channel area 18) exposed to the surface 12a of
the element 12, and the source and drain electrodes 22 and 22
connecting to the source (or drain area) 17 are also formed with an
end surface exposed to the surface 12a of the elements 12. On the
end surface side of the source and drain electrodes 22 and 22, in
order to sufficiently maintain the contact area of the conductive
adhesive described later, terminal sections 22a and 22a are formed
in a condition with their surroundings exposed to the surface 12a.
Furthermore, the surface in the gate electrode 20 on the side
exposed to the surface 12a, also becomes a terminal section 20a in
the present invention.
[0114] The element 12 it is not limited to a TFT, and various
elements such as a silicon base transistor, an SOI (silicon on
insulator) and the like may be applied. However, in this case also,
the terminal sections such as the electrodes are in a condition
exposed to the surface on the opposite side to the separation layer
11.
[0115] Moreover, in the present invention, as the intermediate
layer provided in contact with the separation layer 11, an
SiO.sub.2 film is used, however, other insulating films such as
Si.sub.3N.sub.4 may be used. The thickness of the SiO.sub.2 film
(intermediate layer) is adequately determined corresponding to the
purpose for the formation, and the degree of function to be
demonstrated, however normally around 10 nm to 5 .mu.m is
preferable, and 40 nm to 1 .mu.m is more preferable. The
intermediate layer is formed for various purposes, and functions as
at least one of; a protective layer for physically or chemically
protecting the transferred layer (element 12), an insulating layer,
a conductive layer, a shading layer to laser light, a barrier layer
for preventing migration, and a reflection layer.
[0116] In some cases, the transferred layer (element 12) may be
directly formed on the separation layer 11, by omitting the
formation of the interlayer, such as the SiO.sub.2 film.
[0117] The transferred layer (element 12) includes a thin film
element such as a TFT, as shown in FIG. 2C. As a thin film element,
besides the TFT, there are for example: thin film diodes,
photoelectric transducers including a PIN junction of silicon
(photosensor, solar battery), silicon resistive elements, other
thin film semiconductor devices, electrodes (for example;
transparent electrodes such as ITO and mesa film), switching
devices, memories, actuators such as piezoelectric devices,
micromirrors (piezoelectric thin film ceramics), magnetic recording
thin film heads, coils, inductors, thin film high permeability
materials and micro-magnetic devices composed of combinations
thereof, filters, reflection films, dichroic mirrors, and the
like.
[0118] Such a thin film element (thin film device) is normally
formed by a comparatively high process temperature due to the
forming method therefor. Therefore, in this case, as described
above, the substrate 10 must be a highly reliable material which is
resistant to this process temperature.
[0119] [Second Process]
[0120] On the other hand, as shown in FIG. 3A, a final substrate 14
is prepared. The final substrate 14 is not specifically limited,
and may be a substrate (plate material), specifically a transparent
substrate. Such a substrate may be flat or curved. Further, the
final substrate 14 may be inferior to the original substrate 10 in
characteristics such as heat resistance, corrosion resistance, and
the like. The reason is that; since in this embodiment, the
elements 12 are formed on the original substrate 10, and then the
elements 12 are transferred to the final substrate 14, the
characteristics required for the final substrate 14, specifically
heat resistance, are not dependent on the temperature conditions
when forming the elements 12.
[0121] Therefore, if the maximum temperature when forming the
element 12 is T max, a constituent for the final substrate 14 with
a glass transition point (Tg) or a softening point below T max can
be used. For example, the final substrate 14 can be formed from a
material with a glass transition point or softening point
preferably below 800.degree. C., more preferably below 500.degree.
C., and even more preferably below 320.degree. C.
[0122] As the mechanical characteristics of the final substrate 14,
it is preferable to have a degree of rigidity (strength), however,
it may have flexibility or elasticity.
[0123] As such a constituent for the final substrate 14, there are
various synthetic resins or various glasses. In particular, various
synthetic resins or normal (low melting point) low cost glass are
preferable.
[0124] Examples of synthetic resins include both thermoplastic
resins and thermosetting resins such as; polyolefins, e.g.
polyethylene, polypropylene, ethylene-propylene copolymers, and
ethylene-vinyl acetate copolymers (EVAs); cyclic polyolefins;
modified polyolefins; polyesters such as polyvinyl chloride,
polyvinylidene chloride, polystyrene, polyamides, poly-imides,
polyamide-imides, polycarbonates, poly-(4-methylpentene-1),
ionomers, acrylic resins, polymethyl methacrylate, acrylic-styrene
copolymer (AS resin), butadiene-styrene copolymers, polio
copolymers (EVOHs), polyethylene terephthalate (PET), polybutylene
terephthalate (PBT), polycyclohexane terephthalate (PCT) and the
like; polyethers, polyether-ketones (PEKs), polyether-ether-ketones
(PEEKs), polyether-imides, polyacetals (POMs); polyphenylene
oxides; modified polyphenylene oxides; polyalylates; aromatic
polyesters (liquid crystal polymers), polytetrafluoroethylene,
polyvinylidene fluoride, and other fluorine resins; various
thermoplastic elastomers such as styrene-, polyolefin-, polyvinyl
chloride-, polyurethane-, fluorine rubber-, chlorinated
polyethylene-type, and the like; epoxy resins, phenol resins, urea
resins, melamine resins, unsaturated polyesters, silicone resins,
polyurethanes, and the like; and copolymers, blends, polymer alloys
essentially consisting of these synthetic resins. One or more of
these synthetic resins may be used in combination (for example, as
a composite consisting of at least two layers).
[0125] Examples of glass include, silicate glass (quartz glass),
alkaline silicate glass, soda-lime glass, potash lime glass, lead
(alkaline) glass, barium glass, and borosilicate glass. All the
types of glass other than silicate glass have lower melting points
than that of silicate glass. Moreover, they are comparatively easy
to form and process, and inexpensive, and therefore preferable.
[0126] Furthermore, as the final substrate 14, at the positions
thereon for transferring the elements 12 to be transferred on the
original substrate 10, electrode pads 15 are formed beforehand as
conductive sections in the present invention. The electrode pads 15
are for respectively conducting with the terminal section 20a, and
the terminal sections 22a and 22a shown in FIG. 2C of the elements
12 formed on the original substrate 10, and comprise electrode pads
15a, 15b and 15c provided at positions corresponding the respective
terminal sections. In the present embodiment, as show in FIG. 3B,
wiring 30 is also formed for connecting to these electrode pads
15a, 15b and 15c. Here, the electrode pads 15a, 15b and 15c, for
example as shown in FIG. 3C, are arranged corresponding to the
exposed terminal section 20a of the gate electrode 20, and the
terminal sections 22a and 22a of the source electrode 22 and drain
electrode 22, in the elements 12.
[0127] Next, in this manner, to the final substrate formed with the
wiring 30, as shown in FIG. 4, film-like anisotropic conductive
adhesive 31 is adhered as conductive adhesive to the formation
surface of the electrode pad 15. The film-like anisotropic
conductive adhesive 31 is not specifically limited, and various
kinds can be used. Examples suitable for use include, "3370C" made
by Three Bond Co., Ltd., "Anisorm" made by Hitachi Chemical Co.,
Ltd., and "CP9631SB" made by Sony Chemical Corporation. The
film-like anisotropic conductive adhesive 31 is one where fine
conductive particles are dispersed in an insulative resin and
formed into a film-like adhesive, and it is constituted so as to be
cured by heat pressing. Regarding the film-like anisotropic
conductive adhesive 31 based on such a constitution, when pressed
the dispersed fine conductive particles become continuous in the
direction of pressing, and consequently it attains conductivity in
the direction of pressing. At this time, in the non pressing
direction the fine conductive particles remain in the dispersed
condition, and hence it remains insulating.
[0128] In this manner, after adhering the anisotropic conductive
adhesive 31 onto the final substrate 14, then as shown in FIG. 5,
the original substrate 10 is aligned relative to the final
substrate 14, and adhered so that the element 12 side contacts with
the anisotropic conductive adhesive 31. The alignment of the
original substrate 10 to the final substrate 14, is performed so
that the elements 12 to be transferred are positioned on the
electrode pads 15, more precisely, so that the terminal sections
20a, 22a and 22a of the element 12 are respectively positioned
immediately above the corresponding electrode pads 15a (15b,
15c).
[0129] Then, by pressing one or both of the substrates in a
direction to adhere to each other, and by heating in this
condition, the anisotropic conductive adhesive 31 is cured. In the
present embodiment, as shown in FIG. 5, the original substrate 10
side is pressed. When conducting the press, the elements 12 to be
transferred are selectively pressed, so that the anisotropic
conductive adhesive 31 can be selectively pressed only at the
places positioned immediately beneath the elements 12 to be
transferred. Here, the heating for curing differs depending on the
anisotropic conductive adhesive 31 used, and is performed at around
50.degree. C. to 200.degree. C. The thickness of the film-like
anisotropic conductive adhesive 31 is not specifically limited, but
is preferably around 1 .mu.m to
[0130] In this manner, after selectively pressing the anisotropic
conductive adhesive 31, and then curing by heating, the pressed
area of the anisotropic conductive adhesive 31 becomes a conductive
part 31a having conductivity in the pressing direction.
Consequently, the terminal sections 20a, 22a and 22a of the element
12 respectively conduct with the corresponding electrode pads 15a
(15b, 15c). Moreover, regarding the anisotropic conductive adhesive
31, since the insulativity is still retained in the non pressing
direction, then between the terminal sections 20a, 22a and 22a of
the element 12 and between the corresponding electrode pads 15a
(15b, 15c), the mutual insulation remains, so that they are
respectively electrically independent.
[0131] [Third Process]
[0132] In this manner, after adhering the elements 12 to be
transferred on the original substrate 10, to the final substrate 14
via the anisotropic conductive adhesive 31, exfoliation is produced
in the separation layer 11 between the original substrate 10 and
the elements 12 to be transferred.
[0133] In order to produce exfoliation in the separation layer 11,
as shown in FIG. 6, a light L is selectively irradiated using a
metal mask (not shown) or the like, from the original substrate 10
side to the separation layer 11 of the elements 12 to be
transferred, so as to produce exfoliation in the separation layer
11 and/or at the interface. By producing exfoliation in this
manner, the separation layer 11 is exfoliated and the elements 12
to be transferred are separated from the separation layer 11,
giving the condition where these are adhered via the anisotropic
conductive adhesive 31 to the final substrate 14 side.
[0134] The theory of the occurrence of internal exfoliation and/or
interfacial exfoliation in the separation layer 11 presumes the
occurrence of ablation in the constituents of the separation layer
11, the release of gas contained in the separation layer 11, or a
phase transition such as melting or transpiration generated
immediately after the irradiation.
[0135] The word "ablation" means that solid components (the
constituents of the separation layer 11), which absorbed the
incident light, are photochemically and thermally excited and atoms
or molecules on the surface or inside the solid components are
released by the chain scission. The ablation is mainly observed as
phase transition such as melting or vaporization in the partial or
entire constituents of the separation layer 11. Also, fine foaming
may be formed by the phase transition, resulting in a decreased
adhering force.
[0136] The internal and/or interfacial exfoliation of the
separation layer 11 depends on the composition of the separation
layer 11 and other factors, for example, the type, wavelength,
intensity, and range of the incident light.
[0137] Any type of incident light which causes internal and/or
interfacial exfoliation of the separation layer 11 can be used, for
example, X-rays, ultraviolet rays, visible rays, infrared rays
(heat rays), laser beams, milli-waves, micro-waves, electron rays,
and radiations (.alpha.-rays, .beta.-beta rays, and
.gamma.-rays).
[0138] Among them, laser beams are preferable because they can
easily cause exfoliation (ablation) of the separation layer 11, and
are capable of highly accurate local irradiation. Laser light is
coherent light and preferable for producing exfoliation at the
desired part by irradiating the high powered pulse light the via
the original substrate 10 onto the separation layer. Hence, by
using laser light, it becomes possible to easily and reliably
exfoliate the elements 12.
[0139] Examples of lasers generating the laser beams include
various gas lasers and solid lasers (semiconductor lasers), and
excimer lasers, Nd-YAG lasers, Ar lasers, CO.sub.2 lasers, CO
lasers, and He--Ne lasers may be preferably used.
[0140] The laser light preferably has a wavelength of 100 nm to 350
nm. In this manner, by using the short wavelength laser light,
light irradiation accuracy becomes higher and the exfoliation in
the separation layer 11 can be effectively performed.
[0141] Examples of laser light that satisfy the above conditions
include excimer lasers. The excimer laser is a gas laser which is
capable of outputting laser light with high energy in the short
wavelength UV range. Four typical types of laser light can be
output (XeF=351 nm, XeCl=308 nm, KrF=248 nm, ArF=193 nm) by
combinations of rare gasses (Ar, Kr, Xe, and etc.) and halogen
gasses (F.sub.2, HCl, and etc.) as the laser media. Since the
excimer laser outputs high energy in the short wavelength range, it
can cause ablation of the separation layer 11 in an extremely short
time. Hence it can exfoliate the separation layer 11 without
deteriorating or damaging to the adjacent element 12.
[0142] Alternatively, in the case of imparting exfoliation
characteristic to the separation layer 11 by causing phase changes
such as gas evolution, vaporization and sublimation, the wavelength
of the irradiating laser light is preferably around 350 nm to 1200
nm.
[0143] Laser light of such wavelengths may use a laser light source
or irradiating device widely used in general processing fields,
such as a YAG or gas laser, so that light irradiation can be
performed easily at low cost. By using such laser light of
wavelength in the visible light range, the original substrate 10
need only be visible light transmitting, thus widening the degree
of freedom for selecting the original substrate 10.
[0144] Preferably, the energy density of the incident laser light,
and particularly of the excimer lasers, ranges from approximately
10 to 5,000 mJ/cm.sup.2, and more preferably approximately 100 to
500 mJ/cm.sup.2. The irradiation time preferably ranges from 1 to
1,000 nsec., and more preferably from 10 to 100 nsec. At an energy
density or irradiation time which is lower than the lower limit,
satisfactory ablation will not occur, whereas at an energy density
or irradiation time which is higher than the upper limit, the
element 12 is adversely affected by the incident light passing
through the separation layer 11.
[0145] s a solution to the case where the irradiating light which
has passed through the separation layer 11 reaches and adversely
affects the element 12, for example, there is a method where a
metal film 11 such as tantalum (Ta) is formed on the separation
layer 11. Accordingly, the laser light which has passed through the
separation layer 11 is fully reflected at the interface of the
metal film, and thus does not adversely affect the elements 12
thereabove.
[0146] It is preferable that the incident light including laser
beams be incident on the separation layer with a uniform intensity.
The incident light may be incident on the separation layer 11 from
the direction perpendicular to the separation layer 11 or from a
direction shifted by a given angle from the perpendicular
direction.
[0147] The same position may be irradiated two or more times.
Moreover, the same position or different positions may be
irradiated with different types and/or wavelengths of incident
(laser) light beams two or more times.
[0148] [Fourth Process]
[0149] Next, as shown in FIG. 7, by applying a force on the
original substrate 10 and the final substrate 14 in a direction to
separate both, the original substrate 10 is removed from the final
substrate 14. Here, since by the third process, the separation
layer 11 of the elements 12 to be transferred to the final
substrate 14 has been exfoliated from the elements 12, the elements
12 to be transferred are separated from the original substrate 10.
Moreover, the elements 12 to be transferred are adhered by the
anisotropic conductive adhesive 31 to the desired position of the
final substrate 14, namely the electrode pads 15 in the present
embodiment.
[0150] In the third process, it is desirable to produce complete
exfoliation in the separation layer 11. However, if the adhesive
strength of the anisotropic conductive adhesive 31 for adhering the
elements 12 to be transferred is superior to the adhesive strength
due to the remaining separation layer 11, so that as a result when
the original substrate 10 and the final substrate 14 are separated,
the elements 12 to be transferred are reliably transferred to the
final substrate 14 side, then exfoliation need only be produced in
a part of the separation layer 11.
[0151] By separating the original substrate 10 from the final
substrate 14, as shown in FIG. 7, the elements 12 are transferred
to the plural positions on the final substrate 14.
[0152] Here, regarding the film-like anisotropic conductive
adhesive 31, at the places corresponding to the elements 12 which
are not transferred, adhesion by pressing has not eventuated, and
hence sufficient adhesion between the elements 12 which are not
transferred has not eventuated. Therefore, since the separation
layer 11 of the elements 12 which are not transferred is not
exfoliated, the adhesive strength between the elements 12 and the
anisotropic conductive adhesive 31 is opposed so that they easily
peel off. As a result, the original substrate 10 is easily
separated from the final substrate 14.
[0153] The original substrate 10 on which untransferred elements 12
remain, can be used for successively transferring many elements 12
onto areas of the same final substrate 14 where the elements 12
have not been transferred, or onto another final substrate 14, by
repeating the second and third processes. That is to say, in the
case where the manufacturing method for a device of the present
invention is applied, for example, to a manufacturing method for an
active matrix substrate for an electro-optic device, microscopic
elements 12 such as TFTs can be dispersingly arranged effectively
for each of the many pixels on the substrate.
[0154] There may be a case where the exfoliation residue of the
separation layer 11 is adhered on the element 12 transferred to the
final substrate 14, and it is desirable to completely remove this.
A method for removing the residual separation layer 11 may involve
suitably selecting and using such methods as, for example, washing,
etching, ashing, grinding, or a combination of these.
[0155] Through the abovementioned respective processes it is
possible to selectively transfer the many elements 12 to be
transferred onto the final substrate 14, in the condition as shown
in FIG. 8, where the terminal sections 20a, 22a, and 22a are
respectively adhered to the electrode pads 15a, 15b and 15c. FIG. 8
is a schematic diagram of an active matrix substrate which is a
component of an active matrix type liquid crystal electro-optic
device. Reference symbol 9 in FIG. 8 denotes pixel electrodes.
[0156] Then, the transferred elements 12 are connected for example,
via the electrode pad 15 and the previously formed wiring 30, to
components on the final substrate 14 by other wiring; and are
covered by a desired protective film, and furthermore, a device is
formed by combining the finally obtained device with other
components.
[0157] According to such a device manufacturing method, the many
elements 12 which are to be dispersingly arranged at intervals on
the final substrate 14 can be concentratedly manufactured on the
original substrate 10. Hence, compared to the case where the
elements 12 are directly formed on the final substrate 14, the area
efficiency in the manufacture of the elements 12 can be greatly
increased, and a final substrate 14 with the many elements 12
dispersingly arranged can be effectively manufactured at low
cost.
[0158] Moreover, it becomes easily feasible to select and remove
before transfer, the many elements 12 which are concentratedly
manufactured on the original substrate 10. As a result product
yield rate can be increased.
[0159] Furthermore, since the surface 12a where the terminal
sections 20a, 22a and 22a of the transferred elements 12 are
exposed is adhered via the film-like anisotropic conductive
adhesive 31 to the final substrate 14, the anisotropic conductive
adhesive 31 is directly adhered to the electrode pads 15 on the
final substrate 14. Hence, adhesion of the elements 12 to the final
substrate 14 and conduction of the terminal sections 20a, 22a and
22a with the electrode pads 15a, 15b and 15c can be performed at
the same time. Consequently, the process after transferring, for
conducting the terminal sections with the electrode pad 15 by
wiring is obviated, enabling simplification of the processes.
[0160] Moreover, since the original substrate 10 is substrate for
forming the elements, then when forming the elements 12 on the
original substrate 10, the terminal sections 20a, 22a and 22a
should be provided on the side opposite to the original substrate
10, that is, the outer side. Hence, it is easy to form the terminal
sections 20a, 22a and 22a.
[0161] Furthermore, since, the conductive adhesive is an
anisotropic conductive adhesive 31, the electrode pads 15a (15b,
15c) are each made independently conducting with the many terminal
sections 20a, 22a and 22a of the elements 12. The terminal sections
and the corresponding electrode pads are arranged to oppose each
other, and adhered by the anisotropic conductive adhesive 31 and
pressed. As a result, that the anisotropic conductive adhesive 31
demonstrates its anisotropy and conducts only between the opposing
terminal sections, and electrode pads. Consequently, productivity
can be made extremely good.
[0162] Moreover, since the film-like adhesive is used as the
anisotropic conductive adhesive 31 being a conductive adhesive,
handling is facilitated. Hence productivity can be increased.
[0163] Furthermore, it is possible to laminate and unite the same
or different elements 12. Therefore, by uniting the elements
manufactured under different process conditions, an element having
a laminated structure which is conventionally difficult to
manufacture can be provided, and an element having a
three-dimensional structure can be easily manufactured.
[0164] Moreover, in the device obtained in this manner, since the
surface 12a where the terminal sections 20a, 22a and 22a of the
elements 12 are exposed is adhered via the anisotropic conductive
adhesive 31 to the electrode pads 15 on the substrate (final
substrate 14), then during the manufacture, a process for mounting
the elements 12 on the substrate (final substrate 14) and a process
for conducting the terminal sections 20, 22a and 22a of elements 12
with the electrode pads 15 of the substrate (final substrate 14)
are performed at the same time. Consequently, the process after the
mounting, for conducting the terminal sections 20, 22a and 22a with
the electrode pads 15 by wiring becomes unnecessary, giving high
productivity.
[0165] In the device obtained by such manufacturing methods, since
the elements 12 constituting this are accurately positioned on the
final substrate 14, then different from the macrostructure used in
the conventional microstructure arrangement techniques, the extra
symmetrical circuit structure becomes unnecessary. Hence, extremely
small microscopic blocks on which are formed only the circuits to
meet minimum requirements are possible. Therefore, a very large
number of elements 12 can be concentratedly manufactured on the
original substrate 10 and the cost per element is greatly reduced,
so that the device itself is also reduced in cost.
[0166] In the example, the film-like anisotropic conductive
adhesive 31 serving as the conductive adhesive has its whole
surface affixed to the final substrate. However, as shown in FIG.
9, this may be affixed only on the element transferring area of the
final substrate 14, that is, on the electrode pads 15. In this
case, the wiring 30 for connecting to the electrode pads 15a, 15b
and 15c, may be performed after transferring the elements rather
than being pre-formed. However, in this case, the whole surface of
the electrode pads 15a, 15b and 15c is not covered by the
anisotropic conductive adhesive 31.
[0167] Furthermore, the film-like anisotropic conductive adhesive
31 may be affixed to the terminal section forming surface of the
elements 12, rather than to the electrode pads 15.
[0168] If so the adhesion of the original substrate 10 to the final
substrate 14 by pressing can be performed by appropriately pressing
over the whole surface, rather than being selectively
performed.
Second Embodiment
[0169] The difference of the second embodiment to the first
embodiment is the point that anisotropic conductive adhesive in
paste form, that is, in liquid form, is used as the conductive
adhesive, instead of the film-like anisotropic conductive
adhesive.
[0170] In this embodiment, the final substrate 14 shown in FIG. 3B
formed with the wiring 30 for connecting to the electrode pads 15a,
15b, 15c is prepared, and liquid form anisotropic conductive
adhesive 32 as shown in FIG. 10 is applied on this over the whole
surface by spin coating.
[0171] The liquid form (paste form) anisotropic conductive adhesive
32 is not specifically limited, and various kinds can be used.
Examples suitable for use include "3370G" made by Three Bond Co.,
Ltd. This anisotropic conductive adhesive 32, as with the film-like
anisotropic conductive adhesive 32, is also formed by dispersing
fine conductive particles in an insulative paste, and it is
constituted so as to be cured by heat pressing.
[0172] After whole surface application of this liquid form
anisotropic conductive adhesive 32 onto the final substrate 14 by
spin coating, the original substrate 10 is adhered via the
anisotropic conductive adhesive 32 onto the final substrate 14.
Then, similarly to the first embodiment, only the places
immediately below the elements 12 are selectively pressed and
heated, so that the anisotropic conductive adhesive 31 is cured.
Here, the heating for curing also differs depending on the
anisotropic conductive adhesive 32 used, but is performed at around
50.degree. C. to 200.degree. C. The thickness of the liquid form
anisotropic conductive adhesive 32, it is not specifically limited,
but is preferably around 1 .mu.m to 100 .mu.m.
[0173] Hereunder, similarly to the first embodiment, exfoliation
and separation of substrates is performed, to form the device.
[0174] Also with such a device manufacturing method, and the device
obtained by this, similar effects to the case of the first
embodiment can be obtained.
[0175] Specifically, since the liquid form anisotropic conductive
adhesive 32 is used as the anisotropic conductive adhesive, the
whole surface application can be easily performed by spin coating.
Hence productivity can be increased.
Third Embodiment
[0176] The difference of the third embodiment to the second
embodiment is the point that the liquid form anisotropic conductive
adhesive 32 is selectively arranged by a liquid droplet discharge
method such as an inkjet method, a dispenser method, or the like,
instead of whole surface application by spin coating.
[0177] In this embodiment, the final substrate 14 shown in FIG. 3B
formed with the wiring 30 for connecting to the electrode pads 15a,
15b and 15c may be used. However, as shown in FIG. 11, the final
substrate 14 formed with only the electrode pads 15a, 15b and 15c
before forming the wiring 30 may also be used.
[0178] In the case where the final substrate formed with the only
the electrode pads 15a, 15b and 15c is used, the anisotropic
conductive adhesive 32 being in liquid form is discharged from a
droplet discharge section, for example, an inkjet head H, so as not
to cover the whole surface of these electrode pads 15a, 15b and
15c. Discharge of the anisotropic conductive adhesive 32 may be
performed not for the final substrate 14 but for the terminal
section forming surface 12a.
[0179] To describe an example of the construction of the inkjet
head H, the inkjet head H, as shown in FIG. 12A, comprises for
example a nozzle plate 40 made from stainless steel and a diaphragm
41, with both connected via a partition member (reservoir plate)
42. Between the nozzle plate 40 and the diaphragm 41 are formed by
means of the partition member 42, a plurality of cavities 43 and
liquid reservoirs 44. The respective cavities 43 and the interior
of the liquid reservoirs 44 are filled with discharge liquid, and
the cavities 43 and the liquid reservoirs 44 are communicated via a
supply port 45. In the nozzle plate 40 are formed nozzles 46 for
discharging the discharge liquid from the cavities 43. On the other
hand, in the diaphragm 41 is formed a hole 47 for supplying the
discharge liquid to the liquid reservoirs 44.
[0180] As shown in FIG. 12B, piezoelectric elements (piezo device)
48 are attached to the surface of the diaphragm 41 on the opposite
side to the surface facing the cavities 43. The piezoelectric
elements 48 are positioned between a pair of electrodes 49, and
configured so as to flex and protrude outwards when energized.
Based on such a configuration, the diaphragm 41 to which the
piezoelectric element 48 is attached, is integrated with the
piezoelectric element 48 and thus flexes outwards at the same time.
As a result, the volume of the cavity 43 increases. Consequently,
discharge liquid equivalent to the increased volume flows in to the
interior of the cavity 43 from the liquid reservoir 44 via the
supply port 45. Furthermore, when from such a condition, energizing
of the piezoelectric element 48 is terminated, both the
piezoelectric element 48 and the diaphragm 41 return to their
initial shapes. Therefore, the cavity 43 returns to the initial
volume, and hence the pressure of discharge liquid inside of cavity
43 increases, and a droplet L of the anisotropic conductive
adhesive 32 being the discharge liquid is discharged from the
nozzle 46 towards the final substrate 14.
[0181] The inkjet method for the inkjet head H, is not limited to
the piezo jet type using the piezoelectric element 48, and various
methods can be adopted.
[0182] In this manner, once the anisotropic conductive adhesive 32
has been selectively applied onto electrode pads 15 on the final
substrate 14, or onto the terminal section forming surface 12a of
the elements 12, the original substrate 10 is adhered via this
anisotropic conductive adhesive 32, onto the final substrate 14.
Then, similarly to the second embodiment, pressing and heating is
performed so that the anisotropic conductive adhesive 31 is cured.
Furthermore, wiring (not shown) for connecting to the electrode
pads 15a, 15b and 15c is formed. However, in this case, since the
anisotropic conductive adhesive 32 is selectively applied
previously, the adhesion of the original substrate 10 to the final
substrate 14 by pressing is not selectively performed, and can be
performed by suitably pressing over the whole surface.
[0183] Hereunder, similarly to the first embodiment, exfoliation
and separation of the substrates is performed to form the
device.
[0184] Also with such a device manufacturing method, and the device
obtained by this, similar effects to the case of the first
embodiment can be obtained.
[0185] Furthermore, since the liquid form anisotropic conductive
adhesive 32 can be selectively arranged as the conductive adhesive
on only the desired positions, then by selectively arranging the
anisotropic conductive adhesive 32 onto the electrode pads 15 on
the final substrate 14, loss of adhesive can be reduced. Moreover,
transfer of the elements to the final substrate can be done
easily.
Fourth Embodiment
[0186] The difference of the fourth embodiment to the third
embodiment is the point that instead of selectively arranging the
liquid form anisotropic conductive adhesive 32 by the liquid
droplet discharge method, this is selectively applied by screen
printing. The process after application is the same as for the
third embodiment.
[0187] In this way, as well as obtaining similar effects to the
case of the first embodiment, the effect of reducing the loss of
the adhesive can be also obtained.
Fifth Embodiment
[0188] The difference of the fifth embodiment to the third
embodiment is the point that instead of selectively arranging the
liquid form anisotropic conductive adhesive 32 by the liquid
droplet discharge method, this is selectively applied a
stamper.
[0189] That is to say, in the fifth embodiment, as shown in FIG.
13A, a stamper 33 having convex application sections 33a at
positions for applying the anisotropic conductive adhesive 32 is
prepared. This stamper 33 is inserted into a container 34 storing
the anisotropic conductive adhesive 32, and as shown in FIG. 13B,
the anisotropic conductive adhesive 32 adheres to the application
sections 33a. Next, as shown in FIG. 13C, the stamper 33 is aligned
on the final substrate 14 or on the original substrate 10, and in
this condition, the application sections 33 are pressed for a
predetermined time onto the electrode pads 15 of the final
substrate 14 or onto the elements 12 of the original substrate 10,
and then separated. Therefore, the anisotropic conductive adhesive
32 which is adhered onto the application sections 33a shifts onto
the electrode pads 15 or the elements 12. As a result, the
anisotropic conductive adhesive 32 is selectively applied.
[0190] The processes after application are the same as for the
third embodiment.
[0191] In this way, as well as obtaining a similar effect to the
case of the first embodiment, the effect of being able to reduce
the loss of the adhesive is also obtained. Moreover, this gives a
superior method for mass production.
Sixth Embodiment
[0192] The difference of the sixth embodiment to the third
embodiment is the point that, prior to selectively arranging of the
liquid form anisotropic conductive adhesive 32 by the liquid
droplet discharge method, partitions are formed for enclosing the
positions where the anisotropic conductive adhesive 32 is arranged.
Then the anisotropic conductive adhesive 32 is selectively arranged
within these partitions.
[0193] That is to say, in the sixth embodiment, as shown in FIG.
14, on the electrode pads 15 of the final substrate 14, partitions
34 are formed at peripheral portions enclosing the central upper
surface of the electrode pads 15. Then, the anisotropic conductive
adhesive 32 is selectively arranged inside the partitions 34, by a
liquid droplet discharge method such as the inkjet method or a
dispenser method (FIG. 14 shows the case performed by the inkjet
method). The partitions 34 are formed by applying resin such as
resist and then patterning by a photolithography technique.
Further, after applying the anisotropic conductive adhesive 32, the
partitions 34 are removed by etching.
[0194] The processes after applying the anisotropic conductive
adhesive 32 in this manner and then removing the partitions 34, are
the same as for the third embodiment.
[0195] In this way, as well as obtaining a similar effect to the
case of the first embodiment, by discharging the anisotropic
conductive adhesive 32 into the partitions 34 to arrange this, the
anisotropic conductive adhesive 32 can be more reliably applied to
the desired positions.
Seventh Embodiment
[0196] The difference of the seventh embodiment to the third
embodiment is the point that prior to selectively applying the
anisotropic conductive adhesive 32 onto the final substrate 14,
concavities are formed in the final substrate 14 at junction
positions with the elements 12, and then anisotropic conductive
adhesive 32 is selectively arranged inside the concavities.
[0197] That is to say, as shown in FIG. 15, using a
photolithography technique or an etching technique on the final
substrate 14, concavities 35 are formed, and the electrode pads 15
are formed inside the concavities 35 and at the peripheries. After
this, the anisotropic conductive adhesive 32 is selectively applied
into the concavities 35.
[0198] The processes after application are the same as for the
third embodiment.
[0199] In this way, as well as obtaining a similar effect to the
case of the first embodiment, by discharging the anisotropic
conductive adhesive 32 into the concavities 35 to arrange this, the
anisotropic conductive adhesive 32 can be more reliably applied to
the desired position.
[0200] Furthermore, for example, if the concavities 35 are formed
into shapes to fit the elements 12, then the alignment when
adhering the substrate 10 for transferring and the final substrate
14 can be performed by fitting the elements 12 to the concavities
35. Therefore, alignment when adhering the substrate pairs can be
performed easily and accurately.
[0201] Furthermore, by fitting the elements 12 into the concavity
35, the film thickness of the substrate mounting the elements 12
(the final substrate 14) can be made thinner.
Eighth Embodiment
[0202] The difference of the eighth embodiment to the third
embodiment is the point that prior to selectively applying the
anisotropic conductive adhesive 32 onto the final substrate 14, the
position where the anisotropic conductive adhesive 32 is arranged
on the elements 12 or on the final substrate 14 is subjected to a
lyophilic treatment, and/or the periphery of the position where the
anisotropic conductive adhesive 32 is arranged is subjected to a
liquid repellent treatment.
[0203] Here the liquid repellent treatment can be performed for
example by forming a SAM (Self Assembled Mono layer) film using a
fluororesin such as hexafluoropolypropylene. On the other hand, as
the lyophilic treatment, lyophilication of the irradiated parts can
be performed by selectively performing ultraviolet irradiation
using a mask, on the liquid repellent treated area. Furthermore,
apart from the liquid repellent treatment, by performing plasma
processing with oxygen as the process gas, on the desired area, it
is possible to treat the surface to make the desired part
lyophilic.
[0204] Then, for example, on the electrode pads 15, the parts
except for the area for connecting the wiring 30 are made
lyophilic, or the area for connecting the wiring 30 is made liquid
repellent, and in this condition, the anisotropic conductive
adhesive 32 is discharged and arranged on the lyophilic treated
part by the liquid droplet discharge method.
[0205] In this way, even if the anisotropic conductive adhesive 32
is discharged shifted from the desired position, due to the liquid
repellent treatment at the shifted position, the anisotropic
conductive adhesive 32 is repelled to the desired position, and as
a result, is applied to the desired position. Furthermore, the
anisotropic conductive adhesive 32 discharged to the desired
position, due to the lyophilic treatment, stays in the position and
does not flow to the surroundings.
[0206] Hence, according to the eighth embodiment, as well as
obtaining a similar effect to the case of the first embodiment, the
anisotropic conductive adhesive 32 can be more reliably applied to
the desired position.
[0207] In the above embodiments, anisotropic conductive adhesive is
used as the conductive adhesive, however, the present invention is
not limited to this, and general conductive adhesive may be used
rather than such anisotropic conductive adhesive, that is to say,
conductive adhesive film, or conductive adhesive paste. Here,
examples of conductive adhesive film suitable for use include
"3316" made by Three Bond Co., Ltd. Furthermore, examples of
conductive adhesive paste include "3301" made by Three Bond Co.,
Ltd., "Unimec conductive paste" made by NAMICS Corporation, and
"Ombond" made by OMRON Corporation.
[0208] Such conductive adhesive film or conductive adhesive paste,
in the case where there is one terminal section for the element 12
to be transferred, can be used similarly to the abovementioned
film-like anisotropic conductive adhesive 31 in the first
embodiment, or the paste form anisotropic conductive adhesive 32 in
the second embodiment.
[0209] In the case where there are plural terminal sections for the
element 12, it is necessary to form the conductive adhesive for
adhering to these terminal sections in the condition of
independence for each of the respective terminal sections, and to
insulate between the independent conductive adhesives. The reason
for this is so that short-circuits between the terminal sections by
the conductive adhesive can be prevented.
[0210] Hereunder embodiments are illustrated for the case where
there are plural terminal sections for the elements 12.
Ninth Embodiment
[0211] The difference of the ninth embodiment to the third
embodiment is the point that, as described above, the conductive
adhesive is not anisotropic conductive adhesive but general
conductive adhesive, and the point that the conductive adhesive is
made in a condition of independence by positioning apart for each
of the respective terminal sections, to thereby insulate between
the conductive adhesives.
[0212] That is to say, as shown in FIG. 16, for the electrode pads
15a, 15b and 15c formed on the final substrate 14, there is
provided independently for each, film-like, or paste-like (liquid
form) conductive adhesive 36. Next, the original substrate (not
shown) is adhered, and the respective terminal sections 20a, 22a
and 22a of the elements 12 are adhered via the conductive adhesive
36 to the corresponding electrode pads 15a (15b, 15c). Then, as
necessary, the conductive adhesive 36 is cured by heat treatment or
the like.
[0213] The processes after providing the conductive adhesive 36 in
this manner and then curing as necessary, are the same as for the
first embodiment or the third embodiment.
[0214] In this way, since the surface where the terminal sections
20a, 22a and 22a of the elements 12 are exposed are adhered via the
conductive adhesive 36 to the electrode pads 15a (15b, 15c) on the
final substrate 14, then during manufacture, the process for
mounting the elements 12 on the final substrate 14, and the process
for conducting the terminal sections 20a, 22a, 22a of the elements
12 with the electrode pads 15 of the final substrate 14 can be
performed at the same time. Hence, the process for conducting the
terminal sections 20a, 22a and 22a with the electrode pads 15 by
wiring after mounting can be eliminated, and the processes thus
simplified.
[0215] Furthermore, despite of using general conductive adhesive 36
which is not anisotropic, short-circuits between the terminal
sections 20a, 22a and 22a by the conductive adhesive 36 can be
reliably prevented.
[0216] When arranging the conductive adhesive 36 separated for each
of the respective terminal sections, it is preferable to do this
using paste form adhesive which can be changed to liquid form, as
the conductive adhesive 36, and selectively apply this by the
liquid droplet discharge method. In this case, it is preferable to
more reliably perform the selective application of the conductive
adhesive 36 by performing the lyophilic treatment and the liquid
repellent treatment illustrated in the eighth embodiment.
Tenth Embodiment
[0217] The difference of the tenth embodiment to the ninth
embodiment is the point that, as a method for making the conductive
adhesive 36 in an independent insulated condition for each of the
respective terminal sections, the conductive adhesive 36 is
separated by insulative partitions.
[0218] That is to say, in the tenth embodiment, as shown in FIG.
17, for each of the electrode pads 15a, 15b and 15c corresponding
to the respective terminal sections 20a, 22a and 22a, an insulative
partition 37 is formed similarly to with the sixth embodiment, and
the partition 37 formed by this, functions to separate between the
electrode pads 15a and 15b, and also between the electrode pads 15b
and 15c. When forming the partitions 37, in the case where the
wiring 30 is connected to the electrode pads 15a, 15b and 15c by a
subsequent process, the arrangement is such that the connection
parts remain out of the partition 37.
[0219] Then, after forming the partitions 37 in this way, paste
form adhesive which is adjustable to liquid form is used as the
conductive adhesive 36, and this is selectively discharged and
arranged inside the partitions 37 by the liquid droplet discharge
method. Next, the original substrate (not shown) is adhered, and
the respective terminal sections 20a, 22a and 22a of the elements
12 are adhered via the conductive adhesive 36 to the corresponding
electrode pads 15a (15b, 15c). Then the conductive adhesive 36 is
cured by heat treatment or the like.
[0220] After curing the conductive adhesive 36 in this way, the
wiring 30 is connected to the electrode pads 15a, 15b and 15c as
necessary, and thereafter the subsequent processes are performed
similarly to with the third embodiment.
[0221] In this way, similarly to with the ninth embodiment, the
process for conducting the terminal sections 20a, 22a and 22a with
the electrode pads 15 by wiring after mounting of the elements 12
can be eliminated, and the processes thus simplified.
[0222] Furthermore, since between the terminal sections 20a and 22a
(between the electrode pads) is insulated by the partitions 37
which give separation, short-circuits between the terminal sections
20a, 22a and 22a by the conductive adhesive 36 can be reliably
prevented.
[0223] In the tenth embodiment, after curing the conductive
adhesive 36, the arrangement of the ninth embodiment can be
obtained by selectively removing (etching) only the partition
37.
Eleventh Embodiment
[0224] The difference of the eleventh embodiment to the ninth
embodiment is the point that as a method for making the conductive
adhesive 36 in an independent insulated condition for each of the
respective terminal sections, the conductive adhesive 36 is
arranged inside respective independent concavities.
[0225] That is to say, in the eleventh embodiment, as shown in FIG.
18, respective independent concavities 38 are formed in the surface
layer portion of the final substrate 14, and the electrode pads
15a, 15b and 15c corresponding to the respective terminal sections
20a, 22a and 22a are respectively provided in these concavities 38.
These electrode pads 15a, 15b and 15c are connected to wiring 30
(not shown) as necessary.
[0226] Then after respectively providing the electrode pads 15a
(15b, 15c) in the concavities 38 in this way, paste form adhesive
which is adjustable to liquid form is used as the conductive
adhesive 36, and this is selectively discharged and arranged inside
the partitions 37 by the liquid droplet discharge method. In this
case, it is desirable to more reliably perform selective
application of the conductive adhesive 36, by performing lyophilic
treatment inside the concavities 38 and liquid repellent treatment
of the surroundings of the concavities 38 as illustrated in the
eighth embodiment.
[0227] Next, the original substrate (not shown) is adhered, and the
respective terminal sections 20a, 22a and 22a of the elements 12
are adhered via the conductive adhesive 36 to the corresponding
electrode pads 15a (15b, 15c). Then the conductive adhesive 36 is
cured by heat treatment or the like.
[0228] After curing the conductive adhesive 36 in this way,
thereafter the subsequent processes are performed similarly to with
the third embodiment
[0229] In this way, similarly to with the ninth embodiment, the
process for conducting the terminal sections 20a, 22a and 22a with
the electrode pads 15 by wiring after mounting of the elements 12
can be eliminated, and the processes thus simplified.
[0230] Furthermore, since between the terminal sections 20a and 22a
(between the electrode pads) it insulated by respectively
independently forming the concavities 38, short-circuits between
the terminal sections 20a, 22a and 22a by the conductive adhesive
36 can be reliably prevented.
[0231] In the abovementioned embodiments, the arrangement is such
that the original substrate 10 is the substrate for element
forming, however the present invention is not limited to this. For
example, the substrate for element forming and the original
substrate in the present invention may be separate, and the
elements transferred temporarily from the substrate for element
forming to the original substrate, after which the elements are
again transferred to the final substrate. Furthermore, the
transferring from the substrate for element forming to another
original substrate may be performed once or several times, after
which the elements are transferred to the final substrate via the
original substrate of the present invention.
[0232] Here, devices obtained by such a manufacturing method, are
not specifically limited, and the method is applicable to any
device as long as a constituent is an element such as a
semiconductor element or an optical element. The method can be
applied to various devices, for example, various kinds of
semiconductor devices having switching elements such as memories or
TFTs, electro-optic devices such as organic electroluminescence
devices, liquid crystal displays, electrophoresis apparatus, plasma
display units, and also optical devices such as laser
equipment.
[0233] Examples of electronic equipment of the present invention
are those having the abovementioned electro-optic device as a
display panel, specifically as shown in FIG. 19.
[0234] FIG. 19A is a perspective view showing an example of a
mobile phone. In FIG. 19A, reference numeral 600 denotes the main
body of the mobile phone, and 601 denotes a display panel having
the abovementioned electro-optic device.
[0235] FIG. 19B is a perspective view showing an example of a
portable information processor such as word processor or personal
computer. In FIG. 19B, reference numeral 700 denotes an information
processor, 701 denotes an input section such as keyboard, 703
denotes a main body of the information processor, and 702 denotes a
display panel having the above mentioned electro-optic device.
[0236] FIG. 19C is a perspective view showing an example of a watch
type electronic equipment. In FIG. 19C, reference numeral 800
denotes a main body of the watch and 801 denotes a display panel
having the abovementioned electro-optic device.
[0237] The electronic equipment shown in FIG. 19A to 19C are
furnished with display panels having the abovementioned
electro-optic devices, thus giving a high productivity low cost
product.
[0238] While preferred embodiments of the invention have been
described and illustrated above, it should be understood that these
are exemplary of the invention and are not to be considered as
limiting. Additions, omissions, substitutions, and other
modifications can be made without departing from the spirit or
scope of the present invention. Accordingly, the invention is not
to be considered as being limited by the foregoing description, and
is only limited by the scope of the appended claims.
* * * * *